Iodine-131 is used medically to study the activity of the thyroid gland. iodine – 131 has a half-life of about 8 days. this means that approximately every 8 days, half the mass of the iodine decays into another element. if a container held a mass of 64 milligrams of iodine – 131, how much is left after 40 days?

0.002 mg of sample will be left after 40 days.

Step-by-step explanation:

Half life of the iodine-131 == 8 days

Initial amount of iodine-131 == 64 milligrams = 0.064 g

Amount of iodine-131 left after the time of  40 days = N

Decay constant = = ?

N = 0.002004 g = 0.002 mg

0.002 mg of sample will be left after 40 days.

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.